System and method for safety management in roll-up doors

Abstract

A safety curtain and system includes multiple light emitters and multiple light receivers to detect traffic approaching a doorway. The safety curtain my include pairs of multiple light emitters and receivers positioned on both sides of a passageway (doorway) so as to detect approaching traffic. The multiple light emitters and light receivers may detect a height of an approaching traffic (e.g., person or vehicle) and initiate warning lights of a possible door closing. The detected approach of traffic may cause the door to be stopped, reversed or slow down. The system may include a computer to monitor the signals from the receivers and may control the motion of the door.

What is claimed: 
     
       1. An overhead door assembly comprising:
 a door panel; 
 a motor for facilitating the raising and lowering of the door panel; 
 a controller to control activation of the motor; 
 a first light curtain in communication with the controller, the first light curtain comprising a first array of photo eye sets having a first plurality of light emitters and a first plurality of light receivers, the first array of photo eye sets extending vertically along the doorway and being positioned such that a beam emitted and received by each photo eye set in the first array of photo eye sets extends parallel to the door panel when the door panel is in a closed position, wherein each photo eye set in the first array of photo eye sets is set at a known vertical height along the doorway, and the controller is configured to determine a size of traffic passing through the first light curtain based; 
 a second light curtain in communication with the controller, the second light curtain comprising a second array of photo eye sets having a second plurality of light emitters and a second plurality of light receivers, the second array of photo eye sets extending vertically along the doorway and being positioned such that a beam emitted and received by each photo eye set in the second array of photo eye sensors extends parallel to the door panel when the door panel is in a closed position, wherein each photo eye set in the second array of photo eye sets is set at a known vertical height along the doorway, and the controller is configured to determine a size of traffic passing through the second light curtain; 
 wherein a protected zone monitored by the controller is formed around the door panel between the first light curtain and the second light curtain. 
 
     
     
       2. The overhead door assembly of  claim 1 , wherein the known height of each photo eye set in the first array of photo eye sets is set at a same height as the known height of one photo eye set from the second array of photo eye sets. 
     
     
       3. The overhead door assembly of  claim 1  further comprising a warning light device, the warning light device comprising a plurality of light emitting elements and being in communication with the controller, the controller providing warning signal to the warning light device in conjunction with activating the motor to close the door panel. 
     
     
       4. The overhead door assembly of  claim 3  further comprising at least a second warning light device, the second warning light device comprising a second plurality of light emitting elements and being in communication with the controller, the controller providing the warning signal to the second warning light device in conjunction with activating the motor to close the door panel. 
     
     
       5. The overhead door assembly of  claim 4 , wherein the warning light device is coupled to the first light curtain and the second warning light device is coupled to the second light curtain. 
     
     
       6. The overhead door assembly of  claim 5 , wherein each of the plurality light emitting elements of the warning light device and the second plurality of light emitting elements of the second warning light device are configured to emit at least two colors of light. 
     
     
       7. The overhead door assembly of  claim 6 , wherein the first light curtain transmits at least one first signal to the controller and the second light curtain transmits at least one second signal to the controller, wherein the first signal and the second signal indicate a status of the light beams received by each light receiver in the light curtain. 
     
     
       8. The overhead door assembly of  claim 7 , wherein the controller transmits the warning signal to the first warning light device and the second warning light device in response to receipt of the first signal from the first light curtain or the second signal from the second light curtain. 
     
     
       9. The overhead door assembly of  claim 1 , wherein the first light curtain transmits at least one first signal to the controller and the second light curtain transmits at least one second signal to the controller, wherein the first signal and the second signal indicate a status of the light beams received by each light receiver in the light curtain. 
     
     
       10. The overhead door assembly of  claim 9 , wherein the controller is configured to modify a state of the door panel based on receipt of the first signal or the second signal. 
     
     
       11. The door safety system of  claim 10 , wherein the controller is configured to change the state of the door panel by activating or stopping the motor to slow down, stop, reverse, or start movement of the door based on receipt of the first signal or the second signal.